1. Field of the Invention
This invention relates to intraocular lenses and, more particularly, to intraocular lenses that alter the refractive power of the eye in response to changes in the tension of the ciliary muscle of the eye.
2. Description of the Related Art
The vast majority of cataract operations involve the implantation of an artificial lens following cataract removal. Typically these lenses have a fixed focal length or, in the case of bifocal or multifocal lenses, have several different fixed focal lengths. Such fixed focal-length lenses lack the ability of the natural lens to dynamically change the refractive power of the eye. The various embodiments of the intraocular lens disclosed herein provide an accommodating lens system which alters the refractive power of the eye in response to changes in tension of the ciliary muscle, thereby allowing the lens system to bring into focus on the retina images of objects that are both near and far from the eye.
One aspect of the invention is an accommodating intraocular lens for implantation in an eye having an optical axis. The lens comprises an anterior portion which in turn comprises an anterior viewing element comprised of an optic having refractive power and an anterior biasing element comprising first and second anterior translation members extending from the anterior viewing element. The lens further comprises a posterior portion which in turn comprises a posterior viewing element in spaced relationship to the anterior viewing element and a posterior biasing element comprising first and second posterior translation members extending from the posterior viewing element. The anterior portion and posterior portion meet at first and second apices of the intraocular lens such that a plane perpendicular to the optical axis and passing through the apices is closer to one of said viewing elements than to the other of said viewing elements. The anterior portion and the posterior portion are responsive to force thereon to cause the separation between the viewing elements to change.
Another aspect of the invention is an accommodating intraocular lens for implantation in an eye having an optical axis. The lens comprises an anterior portion, which in turn comprises an anterior viewing element comprised of an optic having refractive power, and an anterior biasing element comprising first and second anterior translation members extending from the anterior viewing element. The lens further comprises a posterior portion which in turn comprises a posterior viewing element in spaced relationship to the anterior viewing element, and a posterior biasing element comprising first and second posterior translation members extending from the posterior viewing element. The anterior portion and posterior portion meet at first and second apices of the intraocular lens. The anterior portion and the posterior portion are responsive to force thereon to cause the separation between the viewing elements to change. The first anterior translation member forms a first anterior biasing angle, as the lens is viewed from the side, with respect to a plane perpendicular to the optical axis and passing through the apices. The first posterior translation member forms a first posterior biasing angle, as the lens is viewed from the side, with respect to the plane. The first anterior biasing angle and the first posterior biasing angle are unequal.
Another aspect of the invention is an accommodating intraocular lens comprising an anterior viewing element comprised of an optic having refractive power of less than 55 diopters and a posterior viewing element comprised of an optic having refractive power. The optics provide a combined power of 15-25 diopters and are mounted to move relative to each other along the optical axis in response to a contractile force by the ciliary muscle of the eye upon the capsular bag of the eye. The relative movement corresponds to change in the combined power of the optics of at least one diopter. Alternatively, the accommodating intraocular lens can further comprise a posterior viewing element comprised of an optic having a refractive power of zero to minus 25 diopters.
A further aspect of the invention is an accommodating intraocular lens comprising an anterior portion which in turn comprises an anterior viewing element which has a periphery and is comprised of an optic having refractive power. The anterior portion further comprises an anterior biasing element comprising first and second anterior translation members extending from the anterior viewing element. The lens further comprises a posterior portion which in turn comprises a posterior viewing element having a periphery, the posterior viewing element being in spaced relationship to the anterior viewing element, and a posterior biasing element comprising first and second posterior translation members extending from the posterior viewing element. The first anterior translation member and the first posterior translation member meet at a first apex of the intraocular lens, and the second anterior translation member and the second posterior translation member meet at a second apex of the intraocular lens, such that force on the anterior portion and the posterior portion causes the separation between the viewing elements to change. Each of the translation members is attached to one of the viewing elements at at least one attachment location. All of the attachment locations are further away from the apices than the peripheries of the viewing elements are from the apices.
A further aspect of the invention is an accommodating intraocular lens comprising an anterior portion comprised of a viewing element. The viewing element is comprised of an optic having refractive power. The lens further comprises a posterior portion comprised of a viewing element. The viewing elements are mounted to move relative to each other along the optical axis in response to force generated by the ciliary muscle of the eye. The lens further comprises a distending portion comprised of a distending member having a fixed end attached to the posterior portion and a free end sized and oriented to distend a portion of the lens capsule such that coupling of forces between the lens capsule and the intraocular lens is modified by the distending portion.
A further aspect of the invention is an accommodating intraocular lens. The lens comprises an anterior portion comprised of an anterior viewing element and an anterior biasing element connected to the anterior viewing element. The anterior viewing element is comprised of an optic having refractive power. The lens further comprises a posterior portion comprised of a posterior viewing element and a posterior biasing element connected to the posterior viewing element. The lens has an optical axis which is adapted to be substantially coincident with the optical axis of the eye upon implantation of the lens. The anterior and posterior viewing elements are mounted to move relative to each other along the optical axis in response to force generated by the ciliary muscle of the eye. The biasing elements are joined at first and second apices which are spaced from the optical axis of the lens. The lens further comprises a distending member extending between the first and second apices.
A further aspect of the invention is an accommodating intraocular lens comprising an anterior portion comprised of a viewing element. The viewing element is comprised of an optic having refractive power. The lens further comprises a posterior portion comprised of a viewing element. The viewing elements are mounted to move relative to each other along the optical axis in response to force generated by the ciliary muscle of the eye. The lens further comprises a retention portion comprised of a retention member having a fixed end attached to the anterior portion and a free end sized and oriented to contact a portion of the lens capsule such that extrusion of the implanted lens through the lens capsule opening is inhibited.
A further aspect of the invention is an accommodating intraocular lens. The lens comprises an anterior portion comprised of a viewing element, the viewing element comprised of an optic having refractive power, and a posterior portion comprised of a viewing element. The viewing elements are mounted to move relative to each other along the optical axis in response to force generated by the ciliary muscle of the eye. The lens further comprises a distending portion comprised of a distending member attached to one of the portions, and oriented to distend the lens capsule such that the distance between a posterior side of the posterior viewing element and an anterior side of the anterior viewing element along the optical axis is less than 3 mm when the ciliary muscle is relaxed and the lens is in an unaccommodated state.
A further aspect of the invention is an accommodating intraocular lens. The lens comprises an anterior portion comprised of a viewing element, the viewing element comprised of an optic having refractive power, and a posterior portion comprised of a viewing element. The viewing elements are mounted to move relative to each other along the optical axis in response to force generated by the ciliary muscle of the eye. The lens further comprises a distending portion comprised of a distending member attached to one of the portions, and oriented to distend the lens capsule. The distending causes the lens capsule to act on at least one of the posterior and anterior portions such that separation between the viewing elements is reduced when the ciliary muscle is relaxed and the lens is in an unaccommodated state.
A further aspect of the invention is an accommodating intraocular lens. The lens comprises an anterior portion comprised of a viewing element, the viewing element comprised of an optic having refractive power, and a posterior portion comprised of a viewing element. The viewing elements are mounted to move relative to each other along the optical axis in response to force generated by the ciliary muscle of the eye. The lens further comprises a distending member attached to the posterior portion. The distending member is separate from the biasing members and reshapes the lens capsule such that force coupling between the ciliary muscle and the lens is modified to provide greater relative movement between the viewing elements when the lens moves between an unaccommodated state and an accommodated state in response to the ciliary muscle.
A further aspect of the invention is an accommodating intraocular lens. The lens comprises an anterior portion comprised of an anterior viewing element and an anterior biasing element connected to the anterior viewing element, the anterior viewing element being comprised of an optic having refractive power. The lens further comprises a posterior portion comprised of a posterior viewing element and a posterior biasing element connected to the posterior viewing element. The lens has an optical axis which is adapted to be substantially coincident with the optical axis of the eye upon implantation of the lens. The anterior and posterior viewing elements are mounted to move relative to each other along the optical axis in response to force generated by the ciliary muscle of the eye. The biasing elements are joined at first and second apices which are spaced from the optical axis of the lens. The lens further comprises first and second distending members. Each of the members is attached to one of the anterior and posterior portions and extends away from the optical axis. The first member is disposed between the apices on one side of the intraocular lens and the second member is disposed between the apices on the opposite side of the intraocular lens. The distending members are oriented to distend portions of the lens capsule such that the viewing elements are relatively movable through a range of at least 1.0 mm in response to contraction of the ciliary muscle.
A further aspect of the invention is an accommodating intraocular lens comprising an anterior portion which is in turn comprised of a viewing element. The anterior viewing element is comprised of an optic having a diameter of approximately 3 mm or less and a refractive power of less than 55 diopters. The lens further comprises a posterior portion comprised of a viewing element. The viewing elements are mounted to move relative to each other along the optical axis in response to force generated by the ciliary muscle of the eye. The lens further comprises a distending portion comprised of a distending member having a fixed end attached to the posterior portion and a free end sized and oriented to distend a portion of the lens capsule such that coupling of forces between the lens capsule and the intraocular lens is increased.
A further aspect of the invention is an accommodating intraocular lens. The lens comprises an anterior portion comprised of a viewing element, the anterior viewing element being comprised of an optic having a refractive portion with a refractive power of less than 55 diopters. The lens further comprises a posterior portion comprised of a viewing element. The lens has an optical axis which is adapted to be substantially coincident with the optical axis of the eye upon implantation of the lens. The posterior viewing element comprises an optic arranged substantially coaxially with the anterior optic on the optical axis of the lens. The posterior optic has a larger diameter than the refractive portion of the anterior optic. The posterior optic comprises a peripheral portion having positive refractive power and extending radially away from the optical axis of the lens beyond the periphery of the refractive portion of the anterior optic, so that at least a portion of the light rays incident upon the posterior optic can bypass the refractive portion of the anterior optic.
A further aspect of the invention is an accommodating intraocular lens. The lens comprises an anterior portion comprised of a viewing element, the anterior viewing element being comprised of an optic having a refractive power of less than 55 diopters. The lens further comprises a posterior portion comprised of a viewing element. The lens has an optical axis which is adapted to be substantially coincident with the optical axis of the eye upon implantation of the lens. The posterior viewing element comprises an optic arranged substantially coaxially with the anterior optic on the optical axis of the lens. The posterior optic has a larger diameter than the anterior optic. The posterior optic comprises a peripheral portion having positive refractive power and extending radially away from the optical axis of the lens beyond the periphery of the anterior optic, so that at least a portion of the light rays incident upon the posterior optic can bypass the anterior optic.
A further aspect of the invention is an intraocular lens. The lens comprises an optic and a pair of elongate members extending from the optic. The members are comprised of a shape memory alloy.
A further aspect of the invention is an accommodating intraocular lens for implantation in an eye having an optical axis and a lens capsule having a capsule opening for receiving the lens. The lens comprises a posterior portion comprised of a posterior viewing element, and an anterior portion comprised of an anterior viewing element. The anterior viewing element is comprised of an optic having refractive power. The viewing elements are mounted to move relative to each other along the optical axis in response to force generated by the ciliary muscle of the eye. The anterior portion is adapted to contact portions of the lens capsule while being spaced from the lens capsule in at least one location so as to provide a fluid flow channel that extends from a region between the viewing elements to a region outside the capsule.
A further aspect of the invention is an accommodating intraocular lens. The lens comprises an anterior portion which in turn comprises an anterior viewing element having a periphery and comprised of an optic having refractive power, and an anterior biasing element comprising at least one anterior translation member attached to a first attachment area on the periphery of the anterior viewing element. The first attachment area has a thickness in a direction substantially perpendicular to the periphery and a width in a direction substantially parallel to the periphery. The ratio of the width to the thickness is equal to or greater than 3.
A further aspect of the invention is a method of manufacturing an intraocular lens having anterior and posterior viewing elements arranged along a common optical axis. The method comprises defining an anterior viewing element mold space and a posterior viewing element mold space, arranging the anterior viewing element mold space and the posterior viewing element mold space along a mold axis substantially coincident with the optical axis of the lens, and molding the anterior viewing element in the anterior viewing element mold space while the anterior viewing element mold space and the posterior viewing element mold space are arranged substantially along the mold axis.
All of these embodiments are intended to be within the scope of the invention herein disclosed. These and other embodiments of the invention will become readily apparent to those skilled in the art from the following detailed description of the preferred embodiments having reference to the attached figures, the invention not being limited to any particular preferred embodiment(s) disclosed.